1. Field of the Invention
This invention relates to a method of controlling exposure for use in a photographic camera, and more particularly to a method of giving information for exposure control based on the brightness of the object to be photographed measured by means of a number of light measuring elements arranged over the whole image area of the image object.
2. Description of the Prior Art
In the photographic camera, it has been known to automatically control the exposure based on the brightness of the object to be photographed measured by a light measuring means incorporated in the camera. As the light measuring means, one or two light measuring elements are used for measuring the scene brightness at a position where the element or elements receive light from the object. Further, there have been known in the art two light measuring systems one of which is a system for measuring the average brightness of the scene and the other of which is a system for measuring the brightness of the central part of the scene.
Recently, there has been proposed a new light measuring system for use in a photographic camera in which a number of light measuring elements are used for measuring the brightness of various parts of the scene and the average value of the maximum brightness and the minimum brightness is calculated based on the outputs of the number of light measuring elements. This system is capable of providing proper exposure even when the scene involves high-light parts and/or shadow parts.
When the brightness of the scene has a large distribution as large as 5EV (exposure value) or more, the exposure must be controlled so that the main subject matter may be photographed with appropriate exposure. In the above described systems, however, the subject matter cannot always be photographed at appropriate exposure. For instance, when the subject matter is in a back light, namely in a bright background, the exposure of the main subject matter becomes under, and when the background is very dark like a spot-lighted subject on a stage the exposure thereof becomes over.